In response to NOT-AG-18-008, we will expand an ongoing cohort study investigating cognitive decline and its impact on chronic disease self-management and functional health status among older adults to include investigations into the presence, roles, and influence of informal caregivers. Our ongoing NIA cohort study, known as ?LitCog? (R01AG030611), includes 900 adults from diverse primary care practices in Chicago who were ages 55 to 74, ?cognitively normal?, and community dwelling when recruited in 2008. Comprehensive cognitive, psychological, social, behavioral, and health assessments are performed every 2.5 years (T1, T2, and T3; 74% retention rate; T4 now active). Subjects were recruited at a younger age (M=63) to capture onset of cognitive decline, incidence of chronic disease, and adjustment to new patient roles. Since enrollment in LitCog, one third of participants have developed mild cognitive impairment (MCI) or dementia, broadly classified within the definition of Alzheimer?s disease and its related dementias (ADRD). LitCog includes examinations of the impact of cognitive impairment (including onset of ADRD) on a patient?s health literacy (HL) skills that determine proper chronic disease self-management, which is strongly linked to functional health status and chronic disease outcomes. We do not, however, account for the involvement of a family member or friend as an ?informal caregiver?. Half of LitCog participants live alone; 1 in 5 are considered socially isolated, and 25% self-report needing assistance in managing their health. Caregivers could be of great benefit, but their ability to effectively support older patients with ADRD may depend on their own HL skills, functional health status, and other psychosocial factors. The availability, but also adequacy of support provided by caregivers may critically determine the health of persons with dementia, yet research on explicit caregiver competencies remains limited. Understanding these associations could inform health system responses. We will recruit informal caregivers to LitCog participants (N=200) with and without ADRD (n=100 with diagnosis), and consent them to participate in structured assessments that align with current data collection activities among enrolled LitCog patients. Our primary aims and hypotheses (H) are to: Aim 1 Investigate the HL skills of informal caregivers to older adults with and without ADRD, and examine associations between caregiver HL and patient functional health status. Aim 2 Evaluate associations between the presence of an informal caregiver with treatment adherence, chronic disease outcomes, and functional health status of older adults with ADRD. Aim 3 Identify factors influencing associations between caregiver HL and patient health outcomes. Aim 4 Determine whether the involvement of an informal caregiver with adequate HL can reduce excess healthcare use among older adults with ADRD.